Research On Vitualization Algorithms In Data Center Optical Network

With the development of Internet applications, high-definition videos and cloud computing, people's demand on network traffic is growing with time. As estimated, the total of IP traffic in 2020 will be three times by now. Enormous demand like this severely challenges the optical network with WDM we now use. Thus how to transport data in Data Transporting Network with higher efficiency and higher flexibility,especially the optimization of data center optical network, has become a main focus in research. As the network demand is gradually exceeding WDM network capacity, flexible grid network has come into sight of the network researchers who are dedicated to develop optical network because of its support on a smaller spectrum. However the cost of upgrading all nodes in transport network to flexible grid nodes is too high to afford, so the co-existence of fixed grid and flexible grid will last for quite a while, which makes it of vital importance to allocate resources with higher efficiency in co-existing network.This paper first points out the shortcomings when WDM optical network comes across the network needs with high flexibility and high bandwidth, introduces and analyzes the fundamental principles and network infrastructure of flex-grid optical network. Then the paper deeply investigates and analyzes the characteristic and methods of routing and spectrum allocation.Then according to the network infrastructure of software defined optical network and mapping strategy of virtual network, we propose an IG-VNE algorithm with coordinated node and link mapping in flex-grid optical network. Experiment results show that coordinated node and link mapping can improve the virtual network acceptance ratio, because of its increasingly greedy concept, virtual network requests with higher require of resources are mapped first, which greatly improves the quality of mapping, making the network resources allocated with higher efficiency.At last,based on the circumstance that fix-grid and flex-grid networks are coexisting on the long-term, we study the virtualization in coexisting network. We propose an ILP model and design an Route and Spectrum Algorithm based on greedy concept,then simulate the algorithm in the NSFnet, results prove that the proposed algorithm can effectively enhance spectrum utilization, which improves the effect of virtualization in coexisting network.